Shotgun muzzle device



E. B. POWELL SHOTGUN MUZZLE DEVICE Dec. 15, 1953 2 Sheets-Sheet 2 Filed Dec. 18, 1948 .EEWAQQ INVENTO&

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Patented Dec. 15, 1953 H UNIT- n STATES m en Q-FFEQE e v ieiisa ihel r 18, 99:5

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This invention relates' genei ell g to imnrqyfed muzzle devices f0: 7 In .t till??? discharging af' s'cattei S o c c arge, concerns more pam c r y n vel ne tr llin the shot pattern and fl rig gun. ,t NJ; l.

'As is well nown in theart, it is o ftendesireple 7 rol qij' 'chokef tubin conjunction with?. s guritih ord'i: tpettein a desiredshot den v patter te p'ai'tiul'a'r J range. Of'eourjsle, eoptim'u h deg jeeof'rc'hoke I) v. varies with the ian'g; aind'- thfeifefo e 'certain'dd} and. paced. from v $13. 1 a el a distance; $1019 justable chok'eshf'ng variable, int'e'rn'sll diam: longer" 1 c etel s hayebeen tei A indjbr objeg'tbf the present iny istjo provid'eierno vel muzzle, device 'cha 'acte "such axilebility. for. ad-V. just-ment to ya conditions of'chok' and adapted also for enting th e gases of combustion s s: ofsuchi'a 5 in a. most effectiil'e, nner. In accordance wit liejinventipn, Iv employ, in combination, an adju b1e'"ch0ketube'adapted to be mounted'in 's" Id relation to'the' muzfzle end of a; gun berrel'tfqjpermit escape of the combustion gaseep'rioi' to exit: ofthe" charge from h me ge. os cnedlabout tnetub' e; and having apertn es th' ughwh1ch'.the, escaping gases are vented; and "ans, rarfiedlby the ca e and engagingthe ghoke jibe tofc'qn'tro'lla'loly vei'r'y its internal diameter. Preferafily, thet ibefw'ilst adapted for bore" constriction in re pqnse to. movement of the gag If" For this nu posej'the cage choke ubemay' xeseni awe e'sfirf ce or may carry a; wedge "ringfopergble 'to'eiiec the defined tube constriction'in 'resnons'e to gage movement. The cage may be threadedly mounted in a manner such thet'iotation of th'eca causes its longitudinal 'movementrelative to the tube, which in turn results in consti ictign of the tube; Desirably, I mount the cage on the choke section of the device anclemplQy a. structui e of such design that si ccessiye 135 0, degree I otetti ns adjust the tube successively to a plurality'qfjp edeter; mined choke congli'tiqns, asio'r'shoi t; medium and long range firing, r espect ively. Detent means. may then be provicledftiorreleesably maintain the g cage in a commonangular position rel'atiyejt'tni the choke section for each of the choke "condi- 1310115. U Y V '7 M A further object of the inventionis the provisien of a novel muz z le device having"firing characteristics similar to the device dis'plosed Patent No. 2,447,205, issued 17"EdWagdifBBidQIj Powell on Augiistl7-,i' 1' 9 48. ""Splecifi 11y that patent shows 'apattern controltuhe untegat its forward enci to' pertnre '(;fi P 1 10 d.

all enlarged -weii enier v tti a f F'g.1; 1

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i kewing; th three ie psyerge sectiqn talgen on line t n, .f t

L0 ccmprises e iy of lQIIE' FHQ BQ l. t mmuitsior em es i fli lyvqefiegiible .???35 9' Ni L5 inte rat d: v 6

7 Q entrance. 9 mm?! he Pubeppirti ne flared slightly outwardly to provide a slightly diverging exit end extent. The tube is made of resilient material tending to restore the tube portions to the positions illustrated in Fig. 3, the portions however being resiliently deflectible inwardly to positions in which their forward ends form a true cylindrical exit tube. Annular groove [8, at the rearward termination of slits I4, is intended to assure deformability of the tube por= tions in the defined manner. Each tube portion presents at its forward end an outwardly facing transversely arcuate wedge surface I9 against which the cage section bears, as will be brought tube 13, and are carried by tubular support 2|, which in turn is secured to muzzle I I of the gun,

as by threaded connection 22. The ribs are preferably of such length that the gap distance D, between the gun muzzle and tube I3, is not longer than the total axial length of a shot charge and following wad normally designed for the gun. Thus, the charge and wad can never be wholly within the gap to permit the rapidly travelling combustion gases to pass around the charge and wad and enter the tube ahead of the charge. The importance of this critical spacial relationship in assuring most satisfactory pattern and range characteristics was brought out in Patent No. 2,447,205.

Cage section l2 includes tubular cage 23 having chevron shaped slots 24 and triangularly shaped slots 25 and 26 disposed across its top and sides to permit upward and lateral venting of the gases of combustion. The cage is disposed about the choke section and is annularly spaced from the choke tube at it. Ring 21 presents an inwardly facing wedge surface 28 substantially complementary to surface [9 on the choke tube, and is carried by and threadedly engages the forward end of the cage at 29. Pin portion 30 of forward gun sight 3| is receivable within registering openings in the cage and ring to angularly interlock the two and prevent their relative rotation. Near its rearward end, the cage presents a reduced diameter bore 32 only slightly larger than the external diameter of the partial cylindrical surface formed by the curved outer surfaces 33 of ribs 20. The cage is rotatably carried upon support portion 21 of the tube section by virtue of threaded connection 34. This threaded connection is sufiiciently loose to permit manual rotation of the cage relative to the tube section in order to allow adjustment of the tube diameter without the use of a tool. Spring pressed detent 35 and cooperating longi tudinal groove 36 are provided in the rearward portion of the tube and cage sections, respectively, and register in the manner illustrated in Fig. 3, when sight 31 is in its upright position.

In use, the device is applied rigidly to muzzle II by threaded or other connection 22. This maintains adjustable tube I3 in substantial axial alinement with the gun barrel and spaced from the barrel the distance D which is preferably not more than the total axial length of a shot charge and following wad normally designed for the gun. By rotation of cage section l2 upon choke section 10, ring 21 may be moved longitudinally of the tube to vary the tube diameter. As will be understood, engagement of wedge surface 28 with surface 19 effects constriction of the tube upon rearward movement of the ring, while subsequent forward ring movement permits the re-' 4 silient tube portions to move outwardly toward their normal condition. The device is adjustable, by successive 360 degree rotations of the cage section, to three choke conditions for short, medium, and long range firing, respectively. As an example, Fig. 4 illustrates the three conditions, giving optimum internal diameter measurements for use with a 10 gauge shot gun. Referring to Fig. 4,'the three degrees of choke are there designated by the reference numerals I, 2 and 3. In all conditions, the rearward integral end of the choke tube measures .790 inch. In

condition Number 1, the entrance or rearward end of the tube converges to a diameter of .749 inch at the approximate longitudinal center I! of the tube. Beyond that point, each tube portion flares slightly outwardly, and the tube thus presents a diverging exit portion whose end diameter is .790 inch. Byrotating the cage section 360 degrees, or a complete revolution, in a clockwise direction as seen from its exit end, the engaging wedge surfaces constrict the adjustable tube to condition 2 of Fig. 4. In that condition, the bore converges to .724 inch and then diverges to .741 inch. Another revolution of the cage section further constricts the tube to condition 3, in which the bore initially converges to .708 inch at point I! and then presents a constant diameter true cylindrical exit bore measuring .708 inch to the forward end of the tube. Detent 35 indicates by a clock the exact angular position for the cage in each condition, and releasably retains the cage in that position.

Upon firing the gun, the gap between the gun barrel and tube l3 permits escape of the explosion gases from behind ashot charge as soon as the charge and its following wad leave the barrel. Some of the gases are, of course, vented from the defined gap through the adjacent rear slots 24 and 25 of the cage, and thus directly to the atmosphere. The rest of the gases travel forwardly into annular space 40 and then outwardly to the atmosphere through the slots in the forward portion of the cage.

Since there are escape slots in the top of the cage but not the bottom, the upwardly escaping gases tend to urge the muzzle downwardly to prevent muzzle jump. Also, impingement of the rapidly travelling gases against the rear edge 4| of the choke tube and the various forward faces 42 of the escape slots tends to move the muzzle device and gun forward to compensate for the normal recoil of the gun.

I claim:

1. A shot gun compensator and variable choke comprising a choke tube adapted to extend forwardly at the forward end of a shot gun barrel,

substantially in axial alinement therewith, said tube having a forward constrictable portion con-- taining longitudinal slits extending rearwardlyfrom its forward end, said forward slit portion of the tube including a rear section containing a. forwardly and gradually tapering bore and a. forward section containing a forwardly and. gradually flaring bore, said tube containing aperture means to the rear of said slits through which the gases of combustion are Vented from the tube upon firing, a, tubular cage disposed about said choke tube, said cage and tube being constructed and arranged to provide a passage extending longitudinally therebetween and in open communication with said aperture means in the tube,

outlet means in the wall of said cage leading exteriorly from said passage to the atmosphere, and,

means for variably constricting the forward slit portion of the tube, said tube having hinge means near the rear of said slits at which the tube flexes upon said constriction.

2. A shot gun compensator and variable choke comprising a choke tube adapted to extend forwardly at the forward end of a shot gun barrel substantially in axial alinement therewith, said tube having a forward constrictable portion containing longitudinal slits extending rearwardly from its forward end, said forward slit portion of the tube including a rear section containing a forwardly and gradually tapering bore and a forward section containing a forwardly and gradually flaring bore, said tube containing aperture means to the rear of said slits through which the gases of combustion are vented from the tube upon firing, a tubular cage disposed about said choke tube, said cage and tube being constructed and arranged to provide a passage extending longitudinally therebetween and in open communication with said aperture means in the tube, outlet means in the wall of said cage leading exteriorly from said passage to the atmosphere, and rotatable wedge means engaged with the forward slit portion of the tube and adjustable to variably constrict the tube, the wall of said tube being locally reduced in thickness at a location near the rear of said slits so that the maximum fiexure of the tube upon said constriction occurs at that location.

3. A shot gun compensator and variable choke comprising a choke tube adapted to extend forwardly at the forward end of a shot gun barrel substantially in axial alinement therewith, said tube having a forward constrictable portion containing longitudinal slits extending rearwardly from its forward end, said forward slit portion of the tube including a rear section containing a forwardly and gradually tapering bore and a forward section containing a forwardly and gradually flaring bore, said tube containing aperture means to the rear of said slits through which the gases of combustion are vented from the tube upon firing, said aperture means extending longitudinally of the tube a distance not greater than the total axial length of the shot column and following wad normally designed for the gun, a tubular cage disposed about said choke tube, said cage and tube being constructed and arranged to provide a passage extending longitudinally therebetween and in open communication with said aperture means in the tube, outlet means in the wall of said cage leading exteriorly from said passage to the atmosphere, and rotatable wedge means engaged with the forward slit portion of the tube and adjustable to variably constrict the tube, the wall of said tube being locally reduced in thickness at a location near the rear of said slits so that the maximum fiexure of the tube upon said constriction occurs at that location.

4. A shot gun compensator and variable choke comprising a choke tube having a rear mounting portion attachable to the muzzle end of a gun substantially in axial alinement therewith, said tube having a forward constrictable portion containing longitudinal slits extending rearwardly from its forward end, said forward slit portion of the tube including a rear section containing a forwardly and gradually tapering bore and a forward section containing a forwardly and gradually fiaring bore, said tube containing aperture means to the rear of said slits and forward of said rear mounting portion and through which the gases of combustion are vented from the tube upon firing, a tubular cage disposed about said choke tube, means connecting the rear portion of said cage to the tube rearwardly of said aperture means, said cage and tube being constructed and arranged to provide a passage extending longitudinally therebetweeen and in open communication with said aperture means in the tube, outlet means in the wall of said cage leading exteriorly from said passage to the atmosphere, and rotatable wedge means carried by the forward end of the cage and engaged with the forward slit portion of the tube for variably constricting the tube, the wall of said tube being locally reduced in thickness at a location near the rear of said slits so that the maximum fiexure of the tube upon said constriction occurs at that location.

5. A'shot gun compensator and variable choke comprising a choke tube adapted to extend forward at the forward end of a shot gun barrel substantially in axial alinement therewith, said tube having a forward constrictable portion containing longitudinal slits extending rearwardly from its forward end, said forward slit portion of the tube including a rear section containing a forwardly and gradually tapering bore and a forward section containing a forwardly and gradually flaring bore, said tube containing aperture means to the rear of said slits through which the gases of combustion are vented from the tube upon firing, a tubular cage disposed about said tube in radially spaced relation thereto to form between the cage and tube a passage in open communication with said aperture means, a threaded joint rotatably connecting the rear portion of the cage to the tube rearwardly of said aperture means, said cage being imperforate opposite said aperture means and having gas outlet means in its wall opposite the slit portion of the tube leading exteriorly from said passage to the atmosphere, and a wedge ring carried by the forward end of the cage for rotation therewith and engaging the forward end of the tube to variably constrict the slit portion of the tube in accordance with said rotation, the wall of said tube containing an annular external groove at the rear ends of said slits and forwardly of said aperture means to form a locally reduced thickness wall ortion at which the tube flexes upon said constriction.

EDWARD BADEN POWELL.

References Cited in the file of this patent UNITED STATES PATENTS Number OTHER REFERENCES The American Rifieman, New Products,

53 p ge 

